Estate Planning in Luxembourg: Forced Heirship, the EU Succession Regulation and Cross-Border Estates

Estate planning in Luxembourg is shaped by two forces that pull in different directions: a civil-law tradition that reserves part of every estate for the children, and a European regulation that lets many residents choose the law of their nationality instead. For the Grand Duchy's large international population, getting the interaction right is the difference between an orderly succession and a costly dispute.

*This article is general information, not legal advice — always consult a notaire for your situation.*

Forced heirship: the réserve héréditaire

Luxembourg law protects certain close heirs — primarily children — through forced heirship. Their guaranteed share is called the réserve héréditaire; the part you may freely give away is the quotité disponible.

The reserve depends on the number of children:

If there are no descendants, Luxembourg law gives more freedom, though a surviving spouse has protected rights (often a choice between a usufruct of the family home or a share of the estate). You cannot simply disinherit a child under Luxembourg domestic law — a will that ignores the réserve can be reduced by the heirs.

The EU Succession Regulation (650/2012)

For deaths from 17 August 2015, Regulation (EU) 650/2012 ("Brussels IV") governs cross-border successions in participating states, including Luxembourg. Two features matter most:

• Default connecting factor — in the absence of a choice, the law of the deceased's last habitual residence applies to the *whole* estate (movable and immovable).
• Choice of law (professio juris) — you may instead choose the law of a country of your nationality to govern your entire succession, by an express declaration in your will.

This is powerful for expats. A UK or Irish national habitually resident in Luxembourg could, by choosing their national law, escape the réserve héréditaire, because common-law systems generally allow freedom to dispose of one's estate. Conversely, without a choice, a foreign national dying resident in Luxembourg will normally have Luxembourg forced-heirship rules applied to their worldwide estate.

The regulation also created the European Certificate of Succession (ECS), a single document heirs can use to prove their status across participating member states, sharply reducing paperwork.

Note on tax

The 650/2012 regulation governs civil succession law, not inheritance tax. Which country taxes the estate is decided separately, by each country's tax rules and any treaties. Choosing English law for the devolution of assets does not change Luxembourg's taxing rights.

Tools of a Luxembourg estate plan

• A will — holographic (handwritten) or notarial; the vehicle for a professio juris choice of law.
• Life insurance (assurance-vie) — a widely used wealth-transfer tool. The death benefit is paid to a named beneficiary and can, within limits, sit outside the ordinary succession, offering flexibility.
• Lifetime gifts (donations) — subject to notarial formality and to potential "reduction" if they encroach on the réserve.
• Matrimonial regime — the marriage contract (community or separation of property) profoundly shapes what actually falls into the estate.

A cross-border worked example

James, a British national, lives in Luxembourg with two children and holds a flat in Luxembourg, a UK rental and investments.

• Without a will: last-habitual-residence rule applies Luxembourg law to everything, so the two children share a 2/3 réserve; James can freely leave only 1/3.
• With a will choosing English law: English freedom of testation applies to the whole estate, letting James, for example, leave more to his spouse — subject still to Luxembourg and UK inheritance-tax exposure on the relevant assets.

The choice, made in a valid will, is what unlocks the flexibility. Coordinating it with the matrimonial regime and life-insurance beneficiary clauses is where a notaire adds most value.

Common pitfalls in cross-border estates

International families in Luxembourg trip over the same recurring issues. Being aware of them early is half the solution.

• Assuming one will covers everything. Assets in a non-EU country, such as a US brokerage account or foreign-situated property, may still require local formalities or a separate will.
• Forgetting the tax/law split. Choosing your national law under Regulation 650/2012 does not move the inheritance-tax charge; heirs can face tax in more than one country.
• Overlooking the matrimonial regime. In a community-property marriage, half the estate may already belong to the surviving spouse before succession even begins.
• Stale beneficiary clauses. Life-insurance and pension nominations override the will and are often left pointing at a former spouse.

A periodic review with a notaire, coordinating will, matrimonial contract and beneficiary designations, prevents most of these from surfacing at the worst possible moment.

Frequently Asked Questions

Can I disinherit my children in Luxembourg?

Not under Luxembourg domestic law — children are protected by the réserve héréditaire. However, if you are a national of a country whose law permits it, you may choose that law under EU Regulation 650/2012 in your will, which can remove the forced share.

Does the EU Succession Regulation decide inheritance tax?

No. Regulation 650/2012 determines which civil law governs who inherits, not which country taxes the estate. Inheritance tax follows separate national rules and treaties, so tax and succession law can point to different countries.

What is a European Certificate of Succession?

It is a standard document created by Regulation 650/2012 that heirs, legatees or executors can use to prove their rights and powers in other participating EU states without repeating national procedures in each country.